Working in Iran and Egypt in the early 1960s, two physicians
named James Halsted and Ananda Prasad examined a group of young
men who were sexually underdeveloped and extremely small for
their age. Through a series of studies, the doctors concluded
that the young men were suffering from extreme zinc deficiency.
They gave them zinc supplements, and, amazingly, the youths began
to grow and their genitals developed normally.

Halsted and Prasad concluded that the problem stemmed from the
young men's diet, which contained virtually no meat (a prime
source of zinc), and consisted largely of unrefined wheat bread.
While wheat and other cereal grains contain zinc, they also have
a lot of phytates, fiber, and lignin, chemicals that bind to zinc
in insoluble complexes that the intestines cannot absorb.

Much of the developing world eats a similar sort of diet, leading
to widespread zinc deficiency, says Public Health's chair of
International Health Robert
Black. Researchers now know that zinc is essential for more than
200 enzyme systems. In addition to slowing growth and
development, zinc deficiency can impair reproduction, immunity,
the senses of taste and vision, and cognition.

What's New at Hopkins:

Public health researchers around the world are discovering that
zinc supplementation can prevent or curb numerous illnesses that
are common in developing countries. A conference on zinc
deficiency and child health and development organized last year
by the School of Public Health highlighted many promising
findings. For example, in his studies in India, Black found that
zinc supplements reduce rates of pneumonia and diarrhea in young
children. Diarrhea is a significant cause of retarded growth and
death in the developing world.

In Papua New Guinea, where 40 percent of the children under five
are infected with malaria parasites, researchers led by Hopkins
immunologist Anuraj Shankar found that zinc and vitamin A
supplements significantly reduced malaria attacks in young
children. "We think zinc supplementation is increasing immunity,
which is involved in controlling malaria parasites," says
Shankar, who is now testing this hypothesis in the lab. Shankar
is also studying whether giving pregnant women zinc supplements
increases their chances of having babies with higher levels of
resistance.

What We Can Do:

Further studies are needed to assess the prevalence of zinc
deficiency and find the most effective way to prevent related
health problems. A year's supply of zinc supplements costs $1 per
child. But researchers also plan to examine strategies for
fortifying foods with zinc.